1. Field of the Invention
This invention relates to a process for producing high-purity glucose (grape sugar) by saccharifying starch with the aid of an enzyme and, more particularly, to such a process for producing glucose wherein the saccharification time of starch is reduced so as to enhance operating efficiency and facilitate quality control.
2. Description of the Prior Art
Generally, the process for producing high-purity glucose by saccharifying starch with the aid of an enzyme can be schematically represented by the following flow sheet:
(Starch milk preparation step).fwdarw.(Starch milk liquefaction step).fwdarw.(Saccharification step).fwdarw.(Filtration step).fwdarw.(Intermediate concentration step) .fwdarw.(Activated carbon decolorization step).fwdarw.(Deionization refining step).
In order to produce high-purity glucose in this process, it is necessary to add a saccharifying enzyme to the liquefied starch solution resulting from the above starch milk liquefaction step and carry out its saccharification until a saccharified solution usually having a glucose content of 97% by weight or greater is obtained. For this purpose, the residence time in a batch type saccharification tank should be as long as 40 to 60 hours at a temperature of 55.degree. to 65.degree. C. Since such a long time is required for saccharification, large-scale saccharification equipment and a large site are needed in order to secure certain outputs. Moreover, such a long saccharification time also requires the implementation of strict quality control in order to inhibit the propagation of microorganisms, suppress the formation of impurities, and control the pH level during saccharification. Thus, the prior art production process leaves much to be desired with regard to the production efficiency and production control of glucose.